Green Biocomposites from Nanoengineered Hybrid Natural Fiber and Biopolymer

The surface grafting of polyhedral oligomeric silsesquioxanes (POSS) nanocages onto keratin biofiber and development of hybrid keratin fiber by dissolution of feather keratin, exfoliation/intercalation of nanoclay in the keratin matrix and regeneration into fiber are reported, respectively. The graft polymerization of POSS on to the surface of keratin fibers was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and confirmed with X-ray photoelectron spectroscopy (XPS). The presence and dispersion of nanoclay, in in situ reinforced and regenerated fiber, was investigated and confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and TEM. The nanomodifications resulted in substantial improvements in the properties of all modified fibers including enhanced thermal stability and reduced moisture uptake compared to unmodified native fibers. The native and modified fibers were further blended with copolymer matrix of 30% styrene with 2-(acryloyloxy) ethyl stearate to prepare the biocomposite films. The properties of the resultant biocomposites were investigated using dynamic mechanical analysis (DMA), flame tests, and SEM. The investigations demonstrated improvements in storage moduli, fiber-matrix adhesion, and reductions in flammability of modified fiber reinforced biocomposites as compared to the neat fiber reinforced biocomposites.